Soiled dishes, flatware and cooking utensils are normally cleaned in automatic dishwashers that confine the objects to be cleaned within a sealed container. An amount of detergent is dispensed into the container and an amount of water is added and the resulting solution is re-circulated by spray apparatus to remove the undesirable materials from the surface of the objects being cleaned.
The significant agitation of the detergent solution being used precludes the use of detergents that generate significant amounts of foam. Excessive foaming of the detergent solution can cause leakage of the foam from the dishwasher. As a result, low foaming detergents are used that generate little foam. By contrast, when dishes, flatware and cookware are to be cleaned by hand by the ordinary consumer, the presence of foam is considered to be a desirable characteristic. While the presence of foam may or may not promote cleaning, consumers engaged in the manual cleaning process consider foam to correlate with cleaning power.
The use of dishwashing detergents on metal cookware also introduces significant constraints. If the detergent is excessively basic or highly alkaline, then aluminum cookware is attacked, degrading the surface of the cookware. Introduction of corrosion inhibitors may minimize the degradation of the aluminum surface; however, some corrosion inhibitors lead to other undesirable effects, such as residues and formulation constraints.
In commercial applications, “open” washing devices are used to clean dishes, flatware, and cookware. Such devices are essentially an open-topped container (i.e., a large sink-like device) having a means of agitation positioned within the device to continuously agitate and heat a detergent solution therein. Because such devices are not closed, the cleaning operation is observable by the operator. Suitable detergents for use in such a device must have adequate cleaning power without the necessity of high-pressure jets that typically are used in an enclosed system (i.e., a household dishwasher).
Further, in the above-described “open” washing devices, a given cleaning solution may remain in use for periods of up to and greater than 4 hours. During this extended period of time, the cleaning solution creates an environment that is conducive to bacteria growth. Most cleaning solutions require the use of an antimicrobial component in order to minimize the growth of bacteria.
Known liquid detergents currently used in open washing devices possess one or more of the following shortcomings: (1) the detergent forms too much foam under agitation such that foam overflows onto the floor next to the open washing device; (2) the detergent forms too little foam under agitation such that an operator doubts whether the detergent is adequately cleaning the cookware; (3) the detergent is unsuitable for use with aluminum cookware; (4) the detergent has a viscosity, which makes dispensing as a liquid, either manually or automatically, difficult; (5) the detergent has an unacceptable shelf life, which prevents the detergent from having satisfactory commercial utility; and (6) the detergent has inadequate antimicrobial properties.
What is needed to the art is a low-foaming liquid detergent, which provides a controlled amount of foam during agitation in an open washing device, provides adequate cleaning power in soft as well as hard water, and is safe to use with aluminum cookware. Further, what is needed to the art is a user-friendly, low-foaming liquid detergent, which is dispensable as a liquid, either manually or automatically, has an acceptable shelf life, and has antimicrobial properties.